Train heating system and trap therefor



IIIIIIIII INVENTOR RA/E5 T J 0am/ you@ ATTORNEY Fa. s, 193s.

E. J. DREWYOUR TRAIN HEATING SYSTEM AND TRAP THEREFOR Filed NOV. 14, 1932 Patented Feb. 5, 1935 'UNITED STATES PATENT OFFICE TRAIN HEATING SYSTEM AND TRAP THEREFOR 3 Claims.

My invention relates to train heating systems. The ordinary train heating system includes a train line running from the locomotive beneath each car of the train to its rear end. In each car, a branch runs from the train line to a heating coil within the car and each such coil has a discharge end controlled by a thermostatically operated valve for discharging condensate formed therein. However, there is quite a little condensate formed in the train line itself, particularly in the coupling sections between cars and at times of low temperatures, especially if the wind is in such direction as to increase the draft against the couplings. Unfortunately, the condensate from the couplings in other parts of the train line cannot pass out thru the traps associated with the car heating coils because such coils are above the level of the train line. The train line condensate, is therefore carried throughout the whole length of the train and discharged `at the rear end of the last car of the train. Such condensate is often suiiicient to fill a large proportion of the free cross-section of the train line so that the train line becomes largely choked 'against passage of steam and the pressure and temperature in the rear portion of the steam line are greatly lowered so that it is difficult to keep the rear cars of the train sufficiently heated.

It has been proposed to trap out the condensate from the train line at various points in its length and such drawing off the condensate would undoubtedly improve the eiciency of the system. However, there are no traps on the market well adapted for use under the conditions o such systems.

The ordinary oat trap is impractical for use in the train lines of train heating systems because, enroute as well as when making up a train, the traps at different points in the train are subjected to widely varying pressures. It is well known that float traps are designed for certain pressures and do not operate satisfactorily at pressures greatly different from the ones for which they are intended. In a train line, the pressure may Vary from 180 to 200 pounds gage near the locomotive to practically zero gage pressure at the end removed from the locomotive. Float operated traps also are subject to freezing when no steam is available.

Aside from the float trap, the only one in ordinary use is the thermostatically operated trap. Such thermostatic traps are impractical for use in train lines of train heating systems, because the temperature of the steam necessarily varies with the pressure and, as mentioned above, the pressures may vary along the train from 200 pounds gage to Zero gage. It would be necessary, therefore, if thermostatic traps were used to adjust them continuously enroute, which is impossible.

It is an object or^ my invention to provide an arrangement whereby the said dimculties may be eliminated or at least minimized.

In order that my invention and its objects and advantages may be fully and readily understood, I will now describe in detail and in connection with the accompanying drawing a train heating system and trap therefor, selected by way of example from a number of possible embodiments of my invention. In the drawing,

Fig. l is a diagrammatic view of a portion of a passenger train having my invention applied thereto.

Fig. 2 is an elevation of a trap appearing in Fig. l.

Fig. 3 is a fragmentary sectional detail of a portion of Fig. 2 illustrating on an enlarged scale a circuit controlling thermometer used in my invention.

Fig. 4 is a sectional detail of an outlet valve whose casing appears in Fig. 2.

Fig. 5 is an elevational View partly in section of a switch box shown in Fig. 2 with cover removed.

Fig. 6 is a sectional detail on the line 6-6 of Fig. 5.

In the drawing, the train illustrated in Fig. 1 includes a locomotive having a boiler 10 connected to a passenger train, one of the cars of which appears at l2. A steam line 14 for heating cars 12 extends from the boiler 10 rearwardly beneath the tender 16 and passenger cars l2 to the last car of the train. Each car has one or more coils such as 18 connected to the steam line for heating the car when desired. Each car has thereon also one or more traps, one of which is illustrated at 20 and which serves also as a connecting point for the heating coils 18. However, I do not limit myself to the number of traps per car, to the location of traps 20 or to associating the traps on each car l2 with the heating coils.

i Trap 2O is connected to. line 14 at the points 22, 22 so steam may low therethru in the desired direction as indicated by the arrows 23, 23.

The coils 18 are shown as connected to the top of the casing of trap 20 by pipe 24. A pipe 26 is provided for discharging water from the casing of trap 20 and shown as connected to the lower portion of such casing. A valve for controlling the out-now thru pipe 26 is shown as having a body 28 close to the casing of the traps, the valve 30 within body 28 being shown as of the double seat type. However, I do not limit myself to any particular type of valve for controlling the outiiow from the trap. As shown, the stem 32 of valve 30 has a means associated therewith tending to open the valve. As shown, such means comprises a spring 34 having one end arranged to Cil push against a normally fixed gland 36 and the otherragainst a collarBrS on the valve stem. HOW- ever, I do not limit myself to spring means for this ',purpose. The valve 30 is held. normally in a closed position. For so holding the valve 30, I have shown ia means comprising a solenoid 39 having a magnetizing'winding 40 and a magnetic vcircuit including an outer shell 42 and a core portion, one part 44 of which is annular in cross-r section and i'lged to shell 42 and extends centrally of yindingflO for part of its length. Theotger part Yof the core portion is movable with respect coil 40 and comprises an armature 4'6iiiged alve stem 32 so as to move therewith, stem nding from valve thru Xed part 44 and re46 [lying on the other side of part .44 from Ythe valve. Armature 46 is slidabie in a centot trallopening intheouter or upper .end of casing .42 and islongl enough to restagainst gar lie close to the part 44 when valve 30 is closed and still project thru or well into the shell soas to `insure thatv the magnetic circuit ofthe shell 42 and core parts 44 and 46 lshallloe of litv magnetic `resistance.: Solenoid 39 oanthere-ore hold valve 30 f shut against the opening means 34 without requiring a largeA holding current in Winding 40. it

will be understoodhowever, thatwinding of solenoid 39 has enough turns and a lowenough resistance'in proportion to thegvoltage of the circuit in which it operates to pull armature-46 in- Wardtoclose valve-30 whenever tsscircuit isclosed.

Thewinding of thesplenoid 39lis connected into a circuit comprising two Wires Sil-and 52Which will` be understood as connected to a suitable source of voltage not shown, but Vindicated thus -V In the-*arrangement illustrated, wire 52 connects Ydirectly to the solenoid winding, but'between wire 56 and the solenoid are connected two -meansfor interrupting the circuit.` 'One such means is a thermostat 54 illustrated in `detail in materialpone end of which extends thru thewall of the trap 2O at pointf56 and projects into the -trap so as to be subject to the temperature therein.

The tube of the thermostat 54 extends outwardly and upwardly from the outer surfaceof the wall of the trap 20 and is filled with a oonducting liquid 58. Mercury is a lling liquid suitable for the purposes of the invention. The Wire is connected to a binding post 60 which extends -thru the wall of the thermostat into the liquid 58 at a point well below the usual level of the surface of such liquid. Above the binding post 60 is a second binding post 62 which also extends thru the Wall of thermostat 54 and into the 'liquid 58.

Binding post 62 is at a level such thatliquid 58 makes `good contact Ytherewith only when the lower and inner end of the tube of the thermostat is at a temperature` above freezing7 preferably -above 40 F. Binding post 62 is connected by wire .64 to a mechanical makeand breakdevice enclosedin casing 66 yand illustrated in detail in Figs. Sand 6. Wire 64 connects to a binding post 68 which extends thru the casing 66 and on its inner end has a contact adaptedto make contact with a contact member '72 on a pivoted throw-over member 74 forming part `of a snapsvvitch mechanism of known design within casing 66. Member 74 is'connected to a binding post `'Z6 by a wirez78 within the casing 66 and binding Thermostat 54 isY of the `thermometer` y type comprising a closed tube of non-conducting Such meanscomprises a float 84 trap 20, the rod 86 ofrwhich isrixed to the shaft 88.` Shaft 88 extends-thru the Wall of the trap and into the casing 66. Within casing 66 the shaft 88 has xed thereto an operated member 90 having a pair of spaced ngersf92,92 which :embrace the tail piece 94 on thepivoted member 'Z41`sothat vwhen shaft 88 is turned kin pne direction or the .otherbythe oat one of the iingersi92ncontacts Iwith tail piece 94 of .the throw-over member'74 and moves such member to either make or break Vtheeircuit` of solenoid 39.r The position of float 84 -is controlled by the vater level in the trap'20:

It will be seen that Ihaveprovided two Ymeans for disabling the hoi-ding means for .the valve 30.3%

One such means isgtemperature controlled and the -other is level controlled. :If thewater levelin f trap-20 rises to a certain point, the oatf84 vwill operate thegthroW-over member '74 to vbreakthe circuit of solenoid 39 and thereby permit the spring 34 to. open the valve 30. When sufficient water has been .discharged'thru valve V30,1float 84 will close the' circuitf solenoid 39 and thereby closethe valve again. If, however, the'water level is. not high venoughtoraise the 4:tloat 84 to permit. .3d

valve 30 to open but'the temperature close tothe bottom of the trap `for any reason should become so low'vaszto approach `the freezing point vof the water in the trap,the mercury column 58y will thermostat 54 is not iniiuenced'by .the tempera- :turewithin trap 20 :exceptrat a level` close to they,1k

bottomv of the trap,ffsothat there is positively no danger that 'the .valve 30 `will freeze shut even in very coldr Weather. l

Whatl 'claim is:

- past its neutral point Aby a level operated means. lo

`contract to a point :below thebinding post 62 503:40 fas lto break thecircuit of the solenoid 39'and .per- 'mitthe valve .30 `to ,openythereby preventing'v freezing ofthe trap. It willfbe seen,.-however, .that the l'. A `trap havingfa valve'forfcontrolling anout-fro let, means for applying a force tending tor-open said valve, .means adaptedto hold said `valve closed, and both temperature operated means and water level operated means ea'chadapted to disable said holding Opel-1. l .f

2. A trap having a'fdischarge valve, means for applying a force tending to opensaid valve, means adapted to hold said valve closed,A and thermomeans to permitsaidvalve to ,55,

static means varranged to beraffected solely by thesis() temperature within said trapat a level close to that of said valve and adapted to disable said holding means to permit said valve to open.

3. A trap having a discharge valve, means for applying a force tending to open said valve, meanszfg adaptedto hold `said valve closedand including an' electricaifcircuit having an electro-magnet connected therein',l and thermostatic means adaptedto* break said circuit and having a part within said trap affected solely by the temperature at a level close to that of saidvalve.

ERNEST J. DREWYOUR. 

